1. Field
The present disclosure relates to a driving method and a driving circuit for a power switching device which may reduce current collapse occurring as electrons are trapped in a semiconductor layer when the power switch device is switched from an off state to an on state.
2. Description of Related Art
A high electron mobility transistor (HEMT) is one type of a power device. The HEMT may include compound semiconductors having different polarizabilities and a two-dimensional electron gas (2DEG) that is used as a carrier may be formed in a channel layer. In the HEMT, a high voltage may be applied to a drain electrode during turn-off and accordingly electrons from a gate electrode may be trapped in a channel supply layer at a drain electrode's side, or at a surface of the channel supply layer.
When the HEMT is switched from an off state to an on state, the trapped electrons fail to escape from a trap site and thus a partial area of the channel is depleted. As a result, on-resistance Rdson increases and thus current collapse may occur. The current collapse may increase resistance, increase heat, and facilitate deterioration in the HEMT. To reduce the current collapse, the trapped electrons are detrapped by applying a positive pulse voltage that is less than a threshold voltage Vth just before a turn-on period or by applying a negative pulse voltage.